The present invention relates to an apparatus for dispensing dry powdered materials and particularly for dispensing accurately metered quantities of dry powdered materials. The apparatus may, for example, be used to dispense metered quantities of dry powdered materials for mixing with liquid to produce a liquid mix in an ice cream freezer, or for producing a beverage in a beverage dispenser. Such powdered material dispensers commonly employ a hopper and a feed auger for feeding dry powdered material from the hopper and for dispensing it through the dispensing outlet in the hopper. Many of the dry powdered materials that are used in the preparation of liquid mixes for ice cream, beverages, and the like are hygroscopic and cohesive and tend to form material bridges in the hopper and across the feed auger. The material bridges interrupt the free flow of material to the feed auger and reduce the amount of material dispensed during each revolution of the auger with a consequent decrease in the charge delivered by the feed auger to the dispensing outlet. Further, material sometime remains in certain areas of the hopper for a long time and can deteriorate or lose its strength and/or flavor.
It has heretofore been proposed, for example as shown in U.S. Pat. Nos. 1,872,028; 2,753,089; 2,794,577; 3,013,701 and 4,207,995, to provide a rotatable agitator wheel in the hopper with teeth on the periphery of the wheel that mesh with the feed auger to rotate the wheel when the feed auger is rotated. While such an agitator wheel can agitate and loosen the material in the area in which the agitator wheel moves, the agitator wheel only extends tangent to the feed auger and does not agitate the material along the length of the auger. Further, there are some areas in the hopper, particularly the larger size hoppers used for storing a large amount of material, in which the material is not agitated and can remain for a long time.